Maybe she could use some kind of plant bio weapon. There is plenty of plants I'm sure of that we don't know about yet so that could open the window for some grounded approaches to the subject of plant weapons.

__________________Kentucky WildcatsBaltimore Ravens"Jedi! You are surrounded, your army is decimated. Make peace with the Force now…for this is your final hour. But know that I, General Grievous, am not completely without mercy. I will grant you a warrior's death. Prepare!" - General Grievous

Maybe she could use some kind of plant bio weapon. There is plenty of plants I'm sure of that we don't know about yet so that could open the window for some grounded approaches to the subject of plant weapons.

That could be very interesting if they wanted to take a grounded approach..

Most chemical weapons, nerve gases etc contain an organic element. Given the refinement required to weaponise a plant enzyme, the effect in the story wouldn't be much different to Ivy using Sarin, or something like that.

My problem with 'gas attacks' as a villain motif is that they are already heavily associated with The Joker and Scarecrow. BB even extended their use to Ra's al Ghul.